Oil boiler

ABSTRACT

An oil boiler includes an outer container having openings at opposite ends, a combustion chamber that covers an opening at an upper end of the outer container and in which a combustion reaction occurs, a lower cover that covers an opening at a lower end of the outer container, a plurality of flue tubes to heat heating water flowing in the outer container by guiding combustion gas, a burner including a fuel nozzle that sprays fuel, an air nozzle that injects air, and a spark plug that ignites a mixture of the fuel and the air, and a flame tube part that defines a tube space by surrounding a partial space in which the mixture is ignited, the flame tube part including a flame tube having an open lower end and a recirculation hole formed through the flame tube such that the combustion gas is introduced into the flame tube.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority to Korean PatentApplication No. 10-2019-0052519, filed in the Korean IntellectualProperty Office on May 3, 2019, the entire contents of which areincorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to an oil boiler.

BACKGROUND

A boiler is an apparatus for heating a desired area by heating fluid ina container. Accordingly, to heat heating water in the boiler, theboiler generally has a structure to generate a flame and combustion gasby causing a combustion reaction using a burner and heat the heatingwater using heat transferred from the flame and heat transferred fromthe combustion gas.

The burner requires fuel so as to cause the combustion reaction.Liquefied petroleum gas or liquefied natural gas, which is a kind offossil fuel, may be used as the fuel. However, diesel fuel or keroseneof an oil type may also be used as the fuel.

In a case where the burner causes a combustion reaction using fuel of anoil type, it is difficult to cause the combustion reaction bycontrolling the amount of the fuel in the same way as when gas is used.Furthermore, when liquid fuel is used, a yellow flame is more likely tobe formed by soot generated due to incomplete combustion. When the sootis generated, passages in the boiler through which combustion gas flowsalong a predetermined path may be blocked. In the case where thecombustion gas does not smoothly flow, the boiler may not normallyoperate.

SUMMARY

The present disclosure has been made to solve the above-mentionedproblems occurring in the prior art while advantages achieved by theprior art are maintained intact.

An aspect of the present disclosure provides a blue flame type oilboiler for generating a blue flame.

The technical problems to be solved by the present disclosure are notlimited to the aforementioned problems, and any other technical problemsnot mentioned herein will be clearly understood from the followingdescription by those skilled in the art to which the present disclosurepertains.

According to an aspect of the present disclosure, an oil boiler includesan outer container having openings at opposite ends thereof and an emptyspace therein, the empty space being connected to the openings at theopposite ends, a combustion chamber that covers an opening at an upperend of the outer container, the combustion chamber being located in theempty space of the outer container and having an interior space in whicha combustion reaction occurs, a lower cover that is spaced apartdownward from the combustion chamber and that covers an opening at alower end of the outer container, a plurality of flue tubes provided inthe empty space of the outer container to heat heating water flowing inthe empty space of the outer container by guiding combustion gasgenerated by the combustion reaction from the interior space of thecombustion chamber to the outside of the lower cover, a burner includinga fuel nozzle that sprays fuel of an oil type into the interior space ofthe combustion chamber, an air nozzle that injects air into the interiorspace, and a spark plug that ignites a mixture of the fuel sprayed andthe air injected, and a flame tube part that defines a tube space bysurrounding, in the interior space, a partial space in which the mixtureof the sprayed fuel and the injected air is ignited, the flame tube partincluding a flame tube having an open lower end and a recirculation holeformed through the flame tube such that the combustion gas in theinterior space is introduced into the flame tube from the outside of theflame tube.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the presentdisclosure will be more apparent from the following detailed descriptiontaken in conjunction with the accompanying drawings:

FIG. 1 is a perspective view of an oil boiler according to an embodimentof the present disclosure;

FIG. 2 is a view illustrating a situation in which a case of the oilboiler is removed according to an embodiment of the present disclosure;

FIG. 3 is an exploded perspective view of the oil boiler according to anembodiment of the present disclosure;

FIG. 4 is a vertical sectional view of the oil boiler according to anembodiment of the present disclosure;

FIG. 5 is a perspective view including a vertical section of the oilboiler according to an embodiment of the present disclosure;

FIG. 6 is an exploded perspective view of a flame tube part of the oilboiler according to an embodiment of the present disclosure;

FIG. 7 is an enlarged vertical sectional view of a portion of the flametube part of the oil boiler according to an embodiment of the presentdisclosure;

FIG. 8 is a sectional view of a part blowing air to a burner of the oilboiler according to an embodiment of the present disclosure;

FIG. 9 is an exploded perspective view of a burner assembly of the oilboiler according to an embodiment of the present disclosure;

FIG. 10 is an exploded perspective view of a damper of the oil boileraccording to an embodiment of the present disclosure;

FIG. 11 is a view illustrating an area in which pressure release holesof the oil boiler are located according to an embodiment of the presentdisclosure;

FIG. 12 is an exploded perspective view of a fuel pump device of the oilboiler according to an embodiment of the present disclosure;

FIG. 13 is a sectional view of an air supply pipe of the oil boileraccording to an embodiment of the present disclosure;

FIG. 14 is a sectional view of a trap device of the oil boiler accordingto an embodiment of the present disclosure;

FIG. 15 is a sectional view illustrating a coupling structure of a flueconnecting adaptor and a flue of the oil boiler according to anembodiment of the present disclosure;

FIGS. 16A to 16D are perspective views illustrating various forms inwhich the flue is connected to the oil boiler according to an embodimentof the present disclosure; and

FIG. 17 is a perspective view of a burner housing of the oil boileraccording to an embodiment of the present disclosure.

DETAILED DESCRIPTION

Hereinafter, some embodiments of the present disclosure will bedescribed in detail with reference to the exemplary drawings. In addingthe reference numerals to the components of each drawing, it should benoted that the identical or equivalent component is designated by theidentical numeral even when they are displayed on other drawings.Further, in describing the embodiment of the present disclosure, adetailed description of well-known features or functions will be ruledout in order not to unnecessarily obscure the gist of the presentdisclosure.

In describing the components of the embodiment according to the presentdisclosure, terms such as first, second, “A”, “B”, (a), (b), and thelike may be used. These terms are merely intended to distinguish onecomponent from another component, and the terms do not limit the nature,sequence or order of the components. When a component is described as“connected”, “coupled”, or “linked” to another component, this may meanthe components are not only directly “connected”, “coupled”, or “linked”but also are indirectly “connected”, “coupled”, or “linked” via a thirdcomponent.

FIG. 1 is a perspective view of an oil boiler 1 according to anembodiment of the present disclosure. FIG. 2 is a view illustrating asituation in which a case 10 of the oil boiler 1 is removed according toan embodiment of the present disclosure. FIG. 3 is an explodedperspective view of the oil boiler 1 according to an embodiment of thepresent disclosure. FIG. 4 is a vertical sectional view of the oilboiler 1 according to an embodiment of the present disclosure. FIG. 5 isa perspective view including a vertical section of the oil boiler 1according to an embodiment of the present disclosure.

Referring to the drawings, the oil boiler 1 according to an embodimentof the present disclosure may be provided in a form in which othercomponents are embedded in a case space 14 of the case 10.

Case 10

The case 10 may have an outer container 21 therein and may be defined bya plurality of walls. In an embodiment of the present disclosure, thecase 10 may have a rectangular parallelepiped shape. The case 10 may beformed in such a manner that an upper wall 11 located on an upper side,a lower wall 13 disposed to be opposite the upper wall 11, and foursidewalls 12 connecting the upper wall 11 and the lower wall 13 definethe case space 14 inside. However, the number of walls and thearrangement thereof are not limited thereto. The sidewalls 12 may extenddownward from the upper wall 11 having a rectangular shape.

In the drawings, handles 1212 are illustrated as being formed on a firstsidewall 121. However, the handles 1212 may be disposed on a thirdsidewall 123 opposite the first sidewall 121. In the drawings,horizontal directions may refer to directions parallel to the planedefined by the x-axis and the y-axis illustrated, and a verticaldirection may refer to a direction defined by the z-axis.

The handles 1212 may be provided on two sidewalls 12 facing each otherin one of the horizontal directions among the sidewalls 12. Accordingly,a user may easily move the oil boiler 1 while holding the handles 1212.

A controller 15 may be disposed on one of the sidewalls 12. Thecontroller 15 may include an operation device 151 and a processor 152.The operation device 151 may include a mechanical structure that can beoperated by the user and a display device capable of representing astate of the oil boiler 1 and may be electrically connected with theprocessor 152. In an embodiment of the present disclosure, thecontroller 15 is illustrated as being disposed on a second sidewall 122.However, the position of the controller 15 is not limited thereto.

The processor 152 may be a component electrically connected tocomponents of the oil boiler 1 to perform control. The processor 152 maybe a component that includes an element capable of a logic operation ofperforming a control command. The processor 152 may include a centralprocessing unit (CPU). The processor 152 may be connected to componentssuch as a differential pressure acquisition device 47, a blower 44, afuel pump device 45, and the like and may transfer signals to thecomponents depending on control commands. The processor 152 may beconnected to various sensors or acquisition devices and may receiveobtained information in the form of a signal. The processor 152 may beelectrically connected with the components. The processor 152 may bewiredly connected to the components, or may additionally have acommunication module capable of wireless communication to communicatewith the components.

The control commands that the processor 152 performs may be stored andutilized on a storage medium, and the storage medium may be, but is notlimited to, a device such as a hard disk drive (HDD), a solid statedrive (SSD), a server, a volatile medium, a nonvolatile medium, or thelike. In addition, data required for the processor 152 to perform tasksmay be additionally stored in the storage medium.

In addition, an expansion tank 16 may be received in the case space 14.The expansion tank 16 may be a container connected with the outercontainer 21 to allow for volume expansion of heating water.

Outer Container 21

The outer container 21 may be a component formed in a cylindrical shapeand may receive a combustion chamber 22, diaphragms 24, flue tubes 23,and the like in a cylindrical empty space 210 formed inside. The outercontainer 21 may be formed of stainless steel. Components embedded inthe outer container 21 may be integrally formed with the outer container21 and may be identically formed of stainless steel to make the entireoil boiler 1 light.

The outer container 21 may have openings formed at opposite ends thereofand may have the empty space 210 formed therein, the empty space 210being connected to the openings at the opposite ends. The outercontainer 21 may have, on a lower side thereof, an outer container inlet211 through which heating water is introduced into the empty space 210and may have, on an upper side thereof, an outer container outlet 212through which the heating water is drained from the empty space 210. Theheating water introduced through the outer container inlet 211 may flowalong the empty space 210 and may be drained through the outer containeroutlet 212. The heating water may be heated by receiving thermal energyfrom the high-temperature flue tubes 23 and the high-temperaturecombustion chamber 22 while flowing in the empty space 210. The heatedheating water may be drained through the outer container outlet 212 andmay perform heating while passing through a heating pipe (notillustrated).

The outer container 21 may include an outer container extension 213 thatextends along the vertical direction and serves as a wall of the outercontainer 21, and may be formed in a cylindrical shape in which a lowerend and an upper end of the outer container extension 213 are open.

Combustion Chamber 22

The opening at the upper end of the outer container 21 may be covered bythe combustion chamber 22. Here, the expression “the combustion chamber22 covers the opening” may mean that the combustion chamber 22completely covers, from the outside, the periphery of the openinglocated at the upper end of the outer container 21. However, thecombustion chamber 22 may be expressed as covering the opening even whenthe combustion chamber 22 is coupled in such a manner that thecombustion chamber 22 is inserted into the opening of the outercontainer 21 and is coupled to an inner circumferential surface of theempty space 210 of the outer container 21 to isolate the empty space 210from the outside, with the periphery of the opening protruding towardthe outside.

The combustion chamber 22 may be a cylindrical component that covers theopening at the upper end of the outer container 21. The combustionchamber 22 may have an interior space 220 therein, and a burner 42inserted into the interior space 220 may cause a combustion reaction.The combustion reaction may occur in the interior space 220 to generatea flame and combustion gas.

The combustion chamber 22 formed in a cylindrical shape may extend fromthe upper end of the outer container 21 toward the lower end of theouter container 21, but may not reach the lower end of the outercontainer 21. The burner 42 may be disposed in the interior space 220 ofthe combustion chamber 22 and may heat the combustion chamber 22 totransfer heat to the heating water. Furthermore, the burner 42 maygenerate the combustion gas by heating gas received in the combustionchamber 22. The combustion gas generated by heating of the burner 42 maybe released from the combustion chamber 22 to the outside through theflue tubes 23. In this process, the combustion gas passing through theflue tubes 23 may heat the heating water passing through the empty space210.

The combustion chamber 22 may include an inner bottom surface 222. Thesurface located at a lower end of the combustion chamber 22 may be theinner bottom surface 222. The inner bottom surface 222 may have bottomsurface through-holes 2221 formed therein, and the flue tubes 23, whichwill be described below, may pass through the bottom surfacethrough-holes 2221. That is, the inner bottom surface 222 may beconnected to the outside by the flue tubes 23. The inner bottom surface222 may be removable from the combustion chamber 22 or may be integrallyformed with the combustion chamber 22. The inner bottom surface 222 maybe formed in a horizontal circular shape. However, the shape of theinner bottom surface 222 is not limited thereto.

An upper end of the combustion chamber 22 may be formed to have adiameter corresponding to the upper end of the outer container 21 andmay be coupled with the upper end of the outer container 21 to close theupper end of the outer container 21 to form the closed empty space 210of the outer container 21. However, the diameter of a combustion chamberextension that extends from the upper end of the outer container 21toward the lower end of the outer container 21 may be smaller than thediameter of the outer container 21. Accordingly, the combustion chamber22 may have a combustion chamber connecting part 2211 that extends fromthe combustion chamber extension to the upper end of the combustionchamber 22 and has a tapered shape. An inner side surface of thecombustion chamber extension may be an inner side surface 221 of thecombustion chamber 22.

The combustion chamber 22 and the outer container 21 may have acylindrical shape, and the combustion chamber extension may have asmaller diameter than the outer container 21 such that the combustionchamber extension is spaced apart from an inner side surface of theouter container 21. Accordingly, a flow space may be formed between theinner side surface of the outer container 21 and an outer side surfaceof the combustion chamber extension.

The heating water may flow from the empty space 210 through the flowspace. The outlet 212 of the outer container 21 that is formed at theupper end of the outer container 21 may be connected to the flow space.Accordingly, the heating water flowing in the flow space may be guidedto the outer container outlet 212 and may be drained through the outercontainer outlet 212. The heating water flowing in the flow space mayfinally receive heat from the combustion chamber 22 heated by the flameof the burner 42 and may be drained through the outer container outlet212 formed on the outer container 21.

An opening formed at the upper end of the combustion chamber 22 may behidden by a combustion chamber cover 28. Components of the burner 42,which will be described below, may pass through the combustion chambercover 28.

Heat Exchanger (Flue Tubes 23, Diaphragms 24, and Lower Cover 29)

The oil boiler 1 according to an embodiment of the present disclosuremay include the heat exchanger. The heat exchanger may include the fluetubes 23 and the diaphragms 24, and these components may be surroundedby the outer container 21, the lower cover 29, and the combustionchamber 22. When the outer container 21 is formed in a cylindricalshape, the heat exchanger may be a shell-and-tube type heat exchanger.The combustion gas may pass through the flue tubes 23, and the heatingwater may flow around the flue tubes 23 in the empty space 210 toexchange heat with the combustion gas. The combustion gas may passthrough the heat exchanger in a lower direction, and accordingly atop-down heat exchanger may be formed.

The lower cover 29 included in the oil boiler 1 may cover the opening atthe lower end of the outer container 21, and the flue tubes 23 may passthrough the lower cover 29. Accordingly, the heating water may belocated in a region of the empty space 210 that is defined by the lowercover 29, the combustion chamber 22, and the outer container 21.

The flue tubes 23 may be disposed between the lower cover 29 and thecombustion chamber 22. The flue tubes 23 may be tubular componentsconnected to the interior space 220 of the combustion chamber 22 and aspace of a condensate receiver 31 formed under the lower cover 29.Accordingly, the flue tubes 23 may guide the combustion gas generatedfrom the combustion gas 22, to a lower place than the lower cover 29through the empty space 210 of the outer container 21. According to anembodiment of the present disclosure, the flue tubes 23 may extend alongthe vertical direction. The heated combustion gas may move downward Dthrough the flue tubes 23. In the process in which the combustion gasmoves, heat exchange between the heating water moving upward through theempty space 210 of the outer container 21 and the combustion gas movingdownward D may be performed through the flue tubes 23.

The flue tubes 23 may be radially disposed from the center of thecircular cross-section of the outer container 21 and the combustionchamber 22. The center of the circular cross-section may be the same asthe center of the diaphragms 24 in a circular plate shape that will bedescribed below. Accordingly, as in an embodiment of the presentdisclosure, the flue tubes 23 may be disposed along one circumference atpredetermined intervals. Alternatively, the flue tubes 23 may bedisposed in two stages by being disposed at predetermined intervalsalong two circumferences having different diameters. However, thearrangement of the flue tubes 23 is not limited thereto.

The flue tubes 23 may be provided in a flat tube type. Specifically,when widths defined in two directions extending to be perpendicular toeach other on a horizontal plane are referred to as a first width and asecond width, the flue tubes 23 may be formed in a shape in which thesecond width of an internal flow passage through which the combustiongas passes is smaller than the first width of the internal flow passage.The outer container 21 may be formed in the shape of a cylinder.Therefore, the first width may be parallel to the radial direction ofthe cylinder, and the second width may be parallel to thecircumferential direction of the cylinder.

A turbulator 26 may be disposed in each of the flue tubes 23. Theturbulator 26 may be an apparatus for turning the flow of the combustiongas passing through the flue tube 23 into a turbulent flow.Specifically, the turbulator 26 may include a plate 261 extending in thevertical direction, a plurality of through-portions 262 formed throughthe plate 261, and a plurality of protrusions 263 protruding from theplate 261. As the plate 261 inserted into the flue tube 23 has theplurality of through-portions 262 and the plurality of protrusions 263,the flow of the combustion gas passing through the flue tube 23 may beturned into a turbulent flow while being hampered or accelerated.

The turbulator 26 may further include a stopper 264 protruding form anupper end of the plate 261 in one direction among the horizontaldirections so as to be stopped by the inner bottom surface 222 of thecombustion chamber 22 when the turbulator 26 is inserted into the fluetube 23 downward D from above the flue tube 23. The stopper 264, whichprotrudes form the plate 261 in one direction among the horizontaldirections, may be bent to more stably fix the plate 261 to the innerbottom surface 222 of the combustion chamber 22. Furthermore, theturbulator 26 formed as described above may be easily separated from theinner bottom surface 222, and accordingly the oil boiler 1 may be easyto clean.

The diaphragms 24 may be disposed in the empty space 210 formed in theouter container 21. The diaphragms 24 may be components formed in acircular plate shape and may be disposed between the lower cover 29 andthe combustion chamber 22 in one direction among the horizontaldirections.

The diaphragms 24 may have through-holes that are formed in positionscorresponding to the positions of the flue tubes 23 and through whichthe flue tubes 23 pass. As the diaphragms 24 divide the empty space 210into a plurality of areas, the diaphragms 24 may form a flow passagethrough which the heating water flowing in the empty space 210 moves. Asillustrated, the diaphragms 24 may make the flow passage of the heatingwater more complex.

The shell-and-tube type heat exchanger having the above-describedstructure may have higher thermal efficiency than other heat exchangersincluding an exemplary heat exchanger of a bottom-up combustion type.Accordingly, the temperature of the finally released combustion gas maybe lower than the temperature of combustion gas released from theexemplary heat exchanger. Accordingly, a flue 53 (refer to FIG. 15) thatis coupled to the oil boiler 1 to finally release the combustion gas tothe outside may be formed of plastic rather than metal.

Condensate Receiver 31

The condensate receiver 31 may be a component that receives and drainscondensate. The condensate receiver 31 may be located under the lowercover 29. Accordingly, the condensate receiver 31 may receive condensatethat falls from a lower surface of the lower cover 29 or the insides ofthe flue tubes 23.

The condensate receiver 31 of the oil boiler 1 according to anembodiment of the present disclosure may include a receiving part 311having a receiving space 3110 between the lower cover 29 and thereceiving part 311 to receive the falling condensate and may furtherinclude a separator 312 connected with the receiving part 311 and a duct33. Furthermore, a condensate pipe 341 may connect the separator 312 anda trap device 32 and may deliver the condensate to the trap device 32.The condensate may be delivered from the separator 312 to the trapdevice 32 through the condensate pipe 341 by the weight of thecondensate, and the combustion gas may be directed upward through theduct 33.

A silencer 35 may be disposed in the separator 312. A situation in whichthe silencer 35 is disposed in the receiving part 311 may be considered.However, in this case, the height of the receiving part 311 in thevertical direction may be increased. Accordingly, as the silencer 35 isdisposed in the separator 312 connected with the duct 33, the height ofthe receiving part 311 may be reduced, and thus the overall height ofthe oil boiler 1 may be reduced.

Specifically, the silencer 35 may be formed of a porous plate and maygenerate resistance to a flow of the combustion gas released to the duct33 through the receiving part 311. As the silencer 35 generates theresistance to the flow of the combustion gas, the processor 152 maycontrol an impeller 441 (refer to FIG. 11) of the blower 44 to rotate athigher speed than when the silencer 35 is not present. Accordingly, alarger amount of air may be supplied to an air nozzle 422 through theblower 44, and the combustion gas may be easily pushed and releasedthrough the flue tubes 23 and the duct 33. Thus, the air or thecombustion gas may be prevented from flowing backward, and ignitionnoise may be reduced. How the processor 152 controls the blower 44depending on the generation of the resistance to the flow of thecombustion gas will be described below in relation to an air supply pipe51.

As the ignition noise is reduced, the combustion chamber 22 may have asmaller size than a combustion chamber of an oil boiler that fails toreduce ignition noise, and the height of the combustion chamber 22 maybe reduced. Thus, an effect of reducing the overall height of the oilboiler 1 may be obtained.

Duct 33

The separator 312 may be connected with the tubular duct 33 extendingupward and may release the combustion gas to the outside through theduct 33. The duct 33 may not extend in only one direction and mayinclude a linear duct portion 331 that extends in the vertical directionand into which the combustion gas released from the outer container 21is introduced, a flue connecting adaptor 333 formed to include an outletof the duct 33, and a horizontal duct portion 332 extending in onedirection among the horizontal directions and connecting the linear ductportion 331 and the flue connecting adaptor 333.

The horizontal duct portion 332 may extend from an upper end of thelinear duct portion 331 in a horizontal direction. The flue connectingadaptor 333 may be connected to a position on the horizontal ductportion 332 that is spaced apart from the linear duct portion 331 in onedirection among the horizontal directions. Accordingly, the linear ductportion 331 and the flue connecting adaptor 333 may be spaced apart fromeach other along the one direction among the horizontal directions.

The overall height of the oil boiler 1 in the vertical direction may beaffected by the length of the duct 33. The duct 33 formed as describedabove may reduce the overall height in the vertical direction whileincreasing the overall length.

The duct 33 may include the linear duct portion 331, the flue connectingadaptor 333, and the horizontal duct portion 332 connecting the linearduct portion 331 and the flue connecting adaptor 333 in one directionamong the horizontal directions. Accordingly, the duct 33 may not beformed straight in one direction and may have an eccentric unbalancedstructure. For example, the flue 53 (refer to FIG. 15) may press theflue connecting adaptor 333 downward D while being coupled to an inletof the duct 33. In this situation, the horizontal duct portion 332 maybe subjected to bending moment because opposite ends of the horizontalduct portion 332 are connected to the force-receiving flue connectingadaptor 333 and the linear duct portion 331 fixed to the separator 312.The force applied when the flue 53 (refer to FIG. 15) is coupled may betransmitted to the linear duct portion 331 through the horizontal ductportion 332 to damage the linear duct portion 331 or the horizontal ductportion 332.

To prevent the damage, the duct 33 may further include a duct support334. The duct support 334 may extend outward from the linear ductportion 331 and may be connected to the horizontal duct portion 332. Theduct support 334 may be seated on a fixing bracket 17 that is fixed to acase bracket 1233 protruding inward from an inner side surface of thecase 10 and that fixes the outer container 21. The duct support 334 maybe seated on the fixing bracket 17. However, the duct support 334 may befixed to the fixing bracket 17 by a fastener even though not seated onthe fixing bracket 17. Likewise, the fixing bracket 167 may also beseated on the case bracket 1233, but may be fixed to the case bracket1233 by a fastener even though not seated on the case bracket 1233.

The fixing bracket 17 may be provided on an outer surface of the outercontainer extension 213 of the outer container 21. As the duct support334 is fixed to the fixing bracket 17, the duct 33 may be supported bythe fixing bracket 17 or the case bracket 1233 through the duct support334 even when the above-described force is applied to the duct 33, andthus damage to the duct 33 may be prevented.

Burner 42

The burner 42 may be a component that ignites fuel of an oil type andair to generate a flame and combustion gas. To enable this operation,the burner 42 may include a fuel nozzle 421, the air nozzle 422, and aspark plug 423.

The fuel nozzle 421 may be a nozzle that sprays the fuel of an oil typeinto the interior space 220 of the combustion chamber 22. The fuelnozzle 421 may be connected to the fuel pump device 45 through a fuelsupply pipe 4512. The fuel nozzle 421 may receive the fuel of an oiltype from the fuel pump device 45 and may spray the fuel into theinterior space 220 at the pressure by which the fuel pump device 45forcibly delivers the fuel. Accordingly, the flow rate at which the fuelnozzle 421 sprays the fuel may be determined by the fuel pump device 45.The fuel nozzle 421 may be disposed to pass through the combustionchamber cover 28. The sprayed fuel of an oil type may be gasified by thehigh-temperature combustion gas circulating through recirculation holes413 of a flame tube part 41 that will be described below.

The air nozzle 422 may inject the air into the interior space 220 of thecombustion chamber 22. The air nozzle 422 may be formed to surround thefuel nozzle 421. The air may be injected through an air injectionopening formed between an outer side surface of the fuel nozzle 421 andan inner side surface of the air nozzle 422. The fuel nozzle 421 mayhave a shape in which a lower end portion thereof has a graduallydecreasing width in the downward direction D, and the air nozzle 422 mayalso have a shape in which a lower end portion thereof has a graduallydecreasing width in the downward direction D.

The ratio of the flow rate of the air injected by the air nozzle 422 tothe flow rate of the fuel sprayed by the fuel nozzle 421 may bemaintained to be a predetermined ratio. The ratio of the flow rate ofthe air injected by the air nozzle 422 to the flow rate of the fuelsprayed by the fuel nozzle 421 may be a ratio suitable for generating ablue flame. The processor 152 may control the air flow rate, which isthe flow rate of the air injected by the air nozzle 422, and the fuelflow rate, which is the flow rate of the fuel sprayed by the fuel nozzle421. The processor 152 may control the blower 44, which supplies the airto the air nozzle 422, to adjust the flow rate of the air supplied tothe air nozzle 422. The processor 152 may control the fuel pump device45, which supplies the fuel to the fuel nozzle 421, to adjust the flowrate of the fuel supplied to the fuel nozzle 421.

The burner 42 may include the spark plug 423. The spark plug 423 may bea component that ignites a mixture of the sprayed fuel and the injectedair. The spark plug 423 may create an electric spark to ignite themixture. A blue flame may be generated as the electric spark is createdin the situation in which the fuel of an oil type is sprayed andthereafter gasified by the circulating combustion gas and the gasifiedfuel and the air are mixed to form the mixture. Accordingly, the oilboiler 1 may be a blue-flame type oil boiler 1.

The burner 42 may further include a burner fixing plate 424 to which thespark plug 423, the fuel nozzle 421, and the air nozzle 422 are fixed.The burner fixing plate 424 may be formed in a plate shape and may befixedly inserted into an upper flame tube 412, which will be describedbelow, to prevent air blown into a burner space 460 (refer to FIG. 8) bythe blower 44 from moving to the flame tube part 41 without passingthrough the air nozzle 422.

The burner fixing plate 424 included in the burner 42 and a burnerhousing 46 that forms the burner space 460 between the burner fixingplate 424 and the combustion chamber cover 28 will be described belowwith reference to FIG. 8.

Flame Tube Part 41

FIG. 6 is an exploded perspective view of the flame tube part 41 of theoil boiler 1 according to an embodiment of the present disclosure. FIG.7 is an enlarged vertical sectional view of a portion of the flame tubepart 41 of the oil boiler 1 according to an embodiment of the presentdisclosure.

The flame tube part 41 will be described below with additional referenceto FIGS. 6 and 7. The flame tube part 41 may be a part in which a flamegenerated by the burner 42 is located. The flame tube part 41 mayinclude lower and upper flame tubes 411 and 412 and the recirculationholes 413.

The recirculation holes 413 may be openings formed in the upper flametube 412. The recirculation holes 413 may be formed such that thecombustion gas passes through the recirculation holes 413. When the fueland the air are emitted at high pressure from the inside of the flametube part 41 through the nozzles 421 and 422, surrounding pressure maybe lowered by the flow of the fluids sprayed at the high pressure, andtherefore the combustion gas located outside the flame tube part 41 maybe introduced through the recirculation holes 413 into the flame tubepart 41, the pressure of which is lowered. The recirculation holes 413may be formed through the upper flame tube 412 such that the combustiongas in the interior space 220 of the combustion chamber 22 is introducedfrom the outside of the lower and upper flame tubes 411 and 412 into atube space 4110 located inside the lower and upper flame tubes 411 and412.

The recirculation holes 413 may be formed in a slot shape that extendsalong the circumferential direction of the upper flame tube 412 thatwill be described below. The recirculation holes 413 may be disposed tobe spaced apart from each other along the circumferential direction ofthe upper flame tube 412.

The combustion gas generated by the burner 42 may meet a combustionguide 27 while flowing downward D, and the flow direction of thecombustion gas may be changed to an upper direction by the combustionguide 27. The combustion gas, the flow direction of which is changed tothe upper direction, may reach the outside of the lower and upper flametubes 411 and 412 and may be introduced into the tube space 4110 throughthe recirculation holes 413. The combustion gas may be circulated inthis way.

The tube space 4110 may be a space in which the mixture of the fuel andthe air is ignited, and the flame tube part 41 in the interior space 220may define the tube space 4110 by surrounding a partial space in whichthe mixture of the sprayed fuel of an oil type and the injected air isignited. Part of the fuel nozzle 421 and part of the air nozzle 422 maybe received in the tube space 4110.

The circulating high-temperature combustion gas may gasify the fuel ofan oil type that is sprayed by the fuel nozzle 421 and that exists in adroplet state. The oil boiler 1 may change the fuel of an oil type to agaseous state and may ignite the gaseous fuel. Accordingly, similarly toa boiler that uses fuel of a gas type, the oil boiler 1 may generate ahigh-temperature blue flame rather than a low-temperature yellow flameand may achieve high fuel efficiency. In addition, the oil boiler 1 mayuse components similar to those of the boiler that uses the fuel of agas type.

As the combustion gas circulates, the temperature of the flame generatedin the lower and upper flame tubes 411 and 412 may be lowered, ascompared with when fuel and air are ignited in a situation in which onlythe fuel and the air exist simply. As the temperature of the flame islowered, the amount of nitrogen oxide generated at high temperature maybe reduced.

The lower and upper flame tubes 411 and 412 may be components that areopen at lower ends and that surround, in the interior space 220, an areato which the fuel is sprayed from the fuel nozzle 421.

The flame tube part 41 may have a first tube part 4111, a second tubepart 4112, and a connecting tube part 4113 connecting the first tubepart 4111 and the second tube part 4112. These tube parts may beincluded in the lower flame tube 411.

Specifically, the first tube part 4111 and the second tube part 4112 maybe formed in a cylindrical shape, and the first tube part 4111 may belocated in a higher position than the second tube part 4112. Thecross-section of the second tube part 4112 may have a larger diameterthan the cross-section of the first tube part 4111. The connecting tubepart 4113 may connect the first tube part 4111 and the second tube part4112. Because there is a difference in diameter between the tube parts4111 and 4112, the connecting tube part 4113 may be formed in afrusto-conical shape. The connecting tube part 4113 may have a shape inwhich the diameter of the cross-section gradually increases in thedownward direction D.

As the flame tube part 41 has the tube parts and has a shape in whichthe diameter of the cross-section gradually increases in the downward Ddirection, a flame having a greater width in a lateral direction than aflame in a straight tube having the same diameter may be formed.

Furthermore, as the flame tube part 41 is formed in a tapered shape asdescribed above, a flame sufficient to produce the combustion gas forheating the heating water and generate radiant heat may be formed eventhough the height of the combustion chamber 22 is reduced.

The flame tube part 41 formed in a tapered shape may form a wide flamerather than a long flame such that the flame does not reach the lowercover 29. As the flame does not reach the lower cover 29, noise and sootmay be reduced during ignition and combustion.

The flame tube part 41 may be divided into the upper flame tube 412 andthe lower flame tube 411. The upper flame tube 412 may have, at an upperend thereof, a tube flange 4121 protruding outward from a cylindricalbody in the radial direction so as to be fixedly coupled to thecombustion chamber cover 28. The tube flange 4121 may be seated on thecombustion chamber cover 28 and may be fastened to the combustionchamber cover 28 by a fastener.

The recirculation holes 413 may be formed in the upper flame tube 412,and the lower flame tube 411 may be coupled to the upper flame tube 412so as to be located below the recirculation holes 413. The upper flametube 412 may have a shape protruding downward D from the combustionchamber cover 28. The lower flame tube 411 may be coupled to a lowerarea of the upper flame tube 412. A method of assembling the upper flametube 412 and the lower flame tube 411 will be described below withadditional reference to FIGS. 6 and 7.

Referring to the drawings, a tube hole 415 may be formed in the upperflame tube 412, and a tube protrusion 414 may be formed on the lowerflame tube 411. As the tube protrusion 414 is inserted into the tubehole 415 and is operated, the upper flame tube 412 and the lower flametube 411 may be coupled together, and the relative positions of theupper flame tube 412 and the lower flame tube 411 may be fixed.

The tube protrusion 414 may be formed on the first tube part 4111.Specifically, the tube protrusion 414 may protrude outward from aposition adjacent to an upper end of the lower flame tube 411. The tubeprotrusion 414 may be formed by folding, toward the outside, a portionextending downward D from the upper end of the lower flame tube 411.However, the forming method is not limited thereto.

A lower hole 4140 may be a hole formed upward from the tube protrusion414 to an upper end of the first tube part 4111. The lower hole 4140 maybe formed through the first tube part 4111 in the radial direction.

The lower hole 4140 may have a larger size than the tube protrusion 414.Specifically, the lower hole 4140 and the tube protrusion 414, asillustrated, may be formed by forming two holes having a predeterminedsize at a predetermined interval along the circumferential direction ofthe first tube part 4111 through punching and thereafter folding, in theradially outward direction, the protruding portion left between the twoholes. However, the forming method is not limited thereto.

The tube hole 415 may be formed through the upper flame tube 412 in theradial direction. Specifically, the tube hole 415 may include a verticalhole portion 4151 extending upward from the lower end of the upper flametube 412. The length of the vertical hole portion 4151 in the verticaldirection is referred to as a first distance.

A horizontal hole portion 4152 may extend from an upper end of thevertical hole portion 4151 in one direction along the circumference ofthe upper flame tube 412. As the upper flame tube 412 is formed in acylindrical shape, the horizontal hole portion 4152 may be formed alongthe circumferential direction of the upper flame tube 412.

The tube hole 415 may include a stopper hole portion 4153 extendingdownward D from a distal end of the horizontal hole portion 4152. In thevertical direction, the stopper hole portion 4153 may have a lengthcorresponding to a second distance smaller than the first distance.

A plurality of tube holes 415 may be formed to be spaced apart from eachother at predetermined intervals along the circumference of the upperflame tube 412, and a plurality of tube protrusions 414 may be formed tobe spaced apart from each other at predetermined intervals along thecircumference of the lower flame tube 411. An equal number of tube holes415 and tube protrusions 414 may be formed, and the tube protrusions 414may be inserted into the tube holes 415, respectively.

The tube protrusions 414 may be inserted into the vertical hole portions4151 by aligning the tube protrusions 414 with the tube holes 415 andthereafter moving the lower flame tube 411 upward. The tube protrusions414 may be moved along the horizontal hole portions 4152 by rotating thelower flame tube 411 about the axis thereof that is oriented in thevertical direction. The lower flame tube 411 may be moved downward D,and the tube protrusions 414 may be stopped by the stopper hole portions4153.

As the lower and upper flame tubes 411 and 412 are assembled by theabove-described method, the lower and upper flame tubes 411 and 412 maynot be easily separated by vibration or shake. The lower flame tube 411and the upper flame tube 412 may simply make contact with each otherwithout being fused or integrated with each other by welding or withoutbeing firmly coupled with each other by a separate fastener such as abolt and nut. Accordingly, the lower and upper flame tubes 411 and 412may not be deformed by heat generated by welding and may be preventedfrom being corroded or damaged by a fastener at high temperature. Inaddition, the amount of heat transferred from the high-temperature lowerflame tube 411 to the upper flame tube 412 may be reduced.

Furthermore, the upper flame tube 412 and the lower flame tube 411 maybe provided as separate objects. The lower flame tube 411 may be formedof a material capable of maintaining the structure and the physicalcharacteristics even at high temperature, and the upper flame tube 412may be formed of a material relatively vulnerable to high temperature.Because a material capable of resisting high temperature is veryexpensive, an economical boiler configuration is possible, as comparedwith when an integrated flame tube is formed.

Combustion Guide 27

The combustion guide 27 may be a component disposed in the interiorspace 220 of the combustion chamber 22 to change the flow direction ofthe combustion gas to the opposite direction. The burner 42 may cause acombustion reaction, and combustion gas generated by the combustionreaction may flow downward D. The combustion gas flowing downward D maymeet the combustion guide 27, and the flow direction of the combustiongas may be changed to the upper direction by the combustion guide 27.Accordingly, the combustion guide 27 may be located below the burner 42and the flame tube part 41.

The combustion guide 27 may include a blocking plate 271, a guide wall272, and a guide leg 273. The blocking plate 271 may be disposed to bespaced apart from the inner side surface 221 of the combustion chamber22 and may be formed in a plate shape. As the interior space 220 of thecombustion chamber 22 is formed in a cylindrical shape, the blockingplate 271 may be formed in a circular plate shape. The combustion gas,while moving downward D, may collide with and reflect back from theblocking plate 271 and may move upward. Furthermore, the blocking plate271 may be located between the inner bottom surface 222 of thecombustion chamber 22 and the burner 42, and accordingly a flame mayreach the blocking plate 271 without making direct contact with theinner bottom surface 222 of the combustion chamber 22. As the flame doesnot make direct contact with the inner bottom surface 222 of thecombustion chamber 22, acoustic boiling noise that heating water belowthe inner bottom surface 222 rapidly boils to generate may be reduced.

The guide wall 272 may extend upward from the blocking plate 271 and maybe formed along the periphery of the blocking plate 271. Accordingly,the guide wall 272 may be formed in an annular shape. The guide wall 272may surround an area above the blocking plate 271, and accordingly thecombustion gas reflected from the blocking plate 271 may move upwardalong the guide wall 272.

Part of the combustion gas moved upward by the guide wall 272 maycirculate into the flame tube part 41 through the recirculation holes413. The remainder may collide with the combustion chamber cover 28 or anozzle flange, and the flow direction may be changed to the downwarddirection D again. Accordingly, the remaining combustion gas may movedownward D through a space formed between the guide wall 272 and theinner side surface 221 of the combustion chamber 22.

The guide leg 273 may be a component extending downward D from theblocking plate 271. The guide leg 273 may extend downward D from theblocking plate 271, and a lower end of the guide leg 273 may makecontact with the inner bottom surface 222 of the combustion chamber 22.Accordingly, the guide leg 273 may support the blocking plate 271 abovethe inner bottom surface 222 of the combustion chamber 22. The blockingplate 271 may be spaced apart from the inner bottom surface 222 of thecombustion chamber 22 by the guide leg 273, and the combustion gasflowing through the space between the blocking plate 271 and the innerside surface 221 of the combustion chamber 22 may move downward Dthrough the flue tubes 23 disposed to pass through the inner bottomsurface 222 of the combustion chamber 22.

Accordingly, the oil boiler 1 may have a reverse combustion structure inwhich the direction of the combustion gas is changed to the oppositedirection by the combustion guide 27. As a result, the combustion gasmay circulate into the flame tube part 41, and the flame may not makedirect contact with the inner bottom surface 222 of the combustionchamber 22, which results in a reduction in acoustic boiling noise ofheating water.

As the oil boiler 1 has the reverse combustion structure, the combustiongas may stay in the combustion chamber 22 for a long period of time, ascompared with when the oil boiler 1 does not have the reverse combustionstructure. Accordingly, heat may be transferred to the top of thecombustion chamber 22, which results in a rise in thermal efficiency.Furthermore, when the oil boiler 1 does not have the combustion guide27, foreign matter such as soot generated in a combustion process may beintroduced into the flue tubes 23. However, in the embodiment of thepresent disclosure in which the oil boiler 1 has the combustion guide27, the foreign matter such as soot may be accumulated on the combustionguide 27. Accordingly, the oil boiler 1 may be more cleanly used, and aheat exchange rate may be raised.

A heat insulating material (not illustrated) may be disposed on thecombustion guide 27 to achieve heat and sound insulation effects. Theheat insulating material may be, but is not limited to, Cerakwool.

Blower 44

FIG. 8 is a sectional view of a part blowing air to the burner 42 of theoil boiler 1 according to an embodiment of the present disclosure. FIG.9 is an exploded perspective view of a burner assembly of the oil boiler1 according to an embodiment of the present disclosure. FIG. 10 is anexploded perspective view of a damper 444 of the oil boiler 1 accordingto an embodiment of the present disclosure. FIG. 11 is a viewillustrating an area in which pressure release holes 5121 of the oilboiler 1 are located according to an embodiment of the presentdisclosure.

Additionally referring to FIGS. 8 to 11, the oil boiler 1 according toan embodiment of the present disclosure may include the burner assembly.The burner assembly may include the burner 42, the blower 44, and thefuel pump device 45 and may further include the flame tube part 41, thecombustion chamber cover 28, the burner housing 46, the air supply pipe51, an ignition transformer 48, and a flame acquisition device 43.

The burner assembly may be provided in such a manner that the burner 42is inserted into and seated in a hole formed in the center of thecombustion chamber cover 28 in a state in which the components of theflame tube part 41 are assembled to the combustion chamber cover 28 byfasteners. As the burner assembly is formed in this manner, thecomponents of the oil boiler 1 may be easily disassembled and cleaned.

Blower 44

The oil boiler 1 may further include the blower 44. The blower 44 may bean apparatus for forcibly delivering, to the air nozzle 422, airsupplied from the outside. The blower 44 may include the impeller 441for compressing air and delivering the compressed air to the air nozzle422, a blower driving motor 443 for transmitting a driving force forrotating the impeller 441 to the impeller 441, and an impeller case 442.

The blower 44 may be connected to the air nozzle 422 through a blowerpipe 464. The blower pipe 464 may connect the blower 44 and the burner42. The damper 444 may be disposed in the blower pipe 464. The damper444 may include a flap 4442 capable of moving between a first positionfor opening the blower pipe 464 and a second position for closing theblower pipe 464.

The damper 444 may further include an annular damper body 4441 that isformed in an annular shape and that has a damper opening 4440 in thecenter thereof. The damper 444 may have a form in which the flap 4442 iscoupled to one side of the annular damper body 4441 so as to berotatable. The annular damper body 4441 may be disposed in a directionoblique to the extension direction of the blower pipe 464, and a lowerside of the annular damper body 1441 may protrude toward the flap 4442such that the flap 4442 has a posture in which the flap 4442 is able tobe seated when rotated by the weight thereof. The flap 4442 may rotateto the second position for covering the damper opening 4440 and mayclose the blower pipe 464. The flap 4442 may rotate to the firstposition spaced apart from the damper opening 4440 and may open theblower pipe 464.

When the blower 44 operates, the flap 4442 may be located at the firstposition by being pressed by an air flow generated by the blower 44.When the blower 44 does not operate, the flap 4442 may be located at thesecond position by the weight of the flap 4442. Accordingly, the flap4442 may close the blower pipe 464 to prevent a situation in which oilmist left in the fuel nozzle 421 after the oil boiler 1 stops operatingflows backward and is located in the air supply pipe 51 and the flue 53or released to the outside to generate unpleasant smell.

When the annular damper body 4441 is disposed in the blower pipe 464, anO-ring 4443 may be mounted on the annular damper body 4441 to foam aseal between the annular damper body 4441 and an inner surface of theblower pipe 464. The O-ring 4443 may be formed of a flexible material.

The impeller 441 may rotate to compress introduced air and blow thecompressed air. The impeller 441 may have a special shape. For example,the impeller 441 may have a shape in which a plurality of helical bladesare disposed on an outer surface of a body having a conical orfrusto-conical shape with a slight slope so as to be spaced apart fromeach other. However, the shape of the impeller 441 is not limitedthereto.

An inlet 4411 of the impeller 441 may be an area corresponding to thevertex of a cone. As the impeller 441 rotates, air introduced throughthe inlet 4411 may be delivered to an outlet of the impeller 441, whichis formed in the radial direction of the impeller 441, through spacesbetween the blades and may be released in a compressed state.

The impeller 441 may be disposed in a receiving space 440 of theimpeller case 442 so as to be directed downward D. However, the shape ofthe impeller 441 and the arrangement direction thereof are not limitedthereto.

The blower driving motor 443 may receive electric power and may beelectrically connected to the processor 151 and controlled by theprocessor 152. The blower driving motor 443 may be connected with theimpeller 441 and may transmit a driving force to the impeller 441 torotate the impeller 441. The blower driving motor 443 may not be a motorcapable of rotating the impeller 441 only at one speed, but may be amotor capable of rotating the impeller 441 at various speeds.Specifically, the blower driving motor 443 may be, but is not limitedto, a brushless DC (BLCD) motor. As the blower driving motor 443 rotatesthe impeller 441 at a higher speed, the flow rate of air delivered tothe air nozzle 422 by the blower 44 may be increased. A specific exampleof controlling the blower driving motor 443 by the processor 152 will bedescribed below in detail in relation to the air supply pipe 51.

The impeller case 442 may be a component having an opening that connectsthe receiving space 440 and an outlet 5120 of the air supply pipe 51.The impeller case 442 may be formed to surround the impeller 441, andthus air may be forcibly delivered well by the impeller 441 withoutleakage.

The impeller case 442 may have a case opening that connects the outlet5120 of the air supply pipe 51 and the receiving space 440. The caseopening may be formed in an area adjacent to the inlet 4411 of theimpeller 441. The air supply pipe 51 may include a pipe having an inletand an outlet at opposite ends thereof, and a flange 512 may extendoutward from one end of the pipe, at which the outlet is formed, tocover the case opening. Accordingly, the flange 512 may be coupled to anarea around the case opening of the impeller case 442.

The air supply pipe 51 may have the pressure release holes 5121. Thepressure release holes 5121 may be formed through the flange 512 and mayconnect the inside and the outside of the impeller case 442. Thepressure release holes 5121 may be formed along the periphery of theoutlet 5120 of the air supply pipe 51 that is the outlet of the pipe.The pressure release holes 5121 may be spaced apart from each otheralong the periphery of the outlet of the pipe.

The pressure release holes 5121 may be formed to prevent combustion gasand air from flowing backward from the combustion chamber 22 to the airsupply pipe 51 by explosion that occurs in a situation such as ignitionof fuel. Even though the combustion gas or the air flows backward to thecase opening through the impeller 441, the combustion gas or the air maybe released to the outside of the impeller case 442 through the pressurerelease holes 5121. Accordingly, the flow rate of air or combustion gasflowing backward to the air supply pipe 51 may be significantly reduced.

The pressure release holes 5121 may be formed in a funnel shape having agradually decreasing diameter toward the outside from the inside of theimpeller case 442. Accordingly, when air is suctioned into the receivingspace 440 from outside the impeller case 442, the flow speed of the airmay be rapidly reduced due to the shape of the pressure release holes5121, and thus noise may be prevented.

Burner Fixing Plate 424 and Burner Housing 46

The burner fixing plate 424 may be formed in the shape of a circularplate, and a portion extending downward D from the periphery of thecircular plate may exist. The portion may make contact with an innerside surface of the upper flame tube 412 to maintain air-tightness andallow the upper flame tube 412 and the burner fixing plate 424 to befixed to each other well.

Specifically, the burner fixing plate 424 may include a circular fixingplate portion 4243 and a peripheral portion 4244 extending downward fromthe periphery of the fixing plate portion 4243 and making contact withan inner side surface of the flame tube part 41. The peripheral portion4244 may make contact with the inner side surface of the upper flametube 412 of the flame tube part 41 and may be disposed such that a lowerend of the peripheral portion 4244 is able to be observed from theoutside through the recirculation holes 413. That is, the lower end ofthe peripheral portion 4244 may be located above an intermediateposition of the recirculation holes 413 with respect to the verticaldirection. Heat transfer to the flame acquisition device 43, which willbe described below, may be reduced by minimizing the area by which theperipheral portion 4244 is exposed through the recirculation holes 413.

The areas of the recirculation holes 413 may be adjusted by adjustingthe height of the peripheral portion 4244 that blocks parts of therecirculation holes 413. Accordingly, the height of the lower end of theperipheral portion 4244 may be determined such that the recirculationholes 413 have the largest size that can be used in the oil boiler 1having a corresponding capacity.

The lower end of the peripheral portion 4244 may be located above therecirculation holes 413. Accordingly, the peripheral portion 4244 andthe recirculation holes 413 may not overlap each other.

The burner housing 46, together with the burner fixing plate 424, mayform the burner space 460 (refer to FIG. 8) that surrounds part of thefuel nozzle 421 and part of the spark plug 423. The blower 44 may blowair into the burner space 460 (refer to FIG. 8), and the burner space460 (refer to FIG. 8) may be connected to the air nozzle 422 to supplythe air into the combustion chamber 22 through the air nozzle 422.

The burner housing 46 may be fixedly seated on an upper surface of thecombustion chamber cover 28. However, the entirety of a lower surface ofthe burner housing 46 that faces the combustion chamber cover 28 may notbe brought into contact with the upper surface of the combustion chambercover 28, and part of the lower surface of the burner housing 46 may bebrought into contact with and coupled with part of the upper surface ofthe combustion chamber cover 28 to form a spacing space between theburner housing 46 and the combustion chamber cover 28.

Specifically, an annular cover contact portion 462 may be formed at alower end of the burner housing 46 and may be brought into contact withand coupled with the combustion chamber cover 28 by a fastener. Part ofthe burner housing 46 that is located inward of the cover contactportion 462 in the radial direction may be spaced apart upward from thecombustion chamber cover 28 to form the burner space 460.

Due to this structure, heat transferred to the burner housing 46 may beless than heat transferred from the high-temperature combustion chamber22 to the combustion chamber cover 28 when the burner housing 46 and theentire combustion chamber cover 28 make contact with each other. Thedegree to which the flame acquisition device 43 is heated may bedecreased as the degree to which the burner housing 46 is heated isreduced.

An annular cover packing 461 may be disposed to prevent leakage ofcombustion gas or air between the burner housing 46 and the combustionchamber cover 28. The cover packing 461 may be disposed between theburner housing 46 and the combustion chamber cover 28 to seal the burnerspace 460.

Furthermore, part of the burner housing 46 that is located outward ofthe cover contact portion 462 in the radial direction may include partof the outside of a transformer fixing part 465 and part of the outsideof the blower pipe 464. The oil boiler 1 according to an embodiment ofthe present disclosure may include the ignition transformer 48 thatreceives general power, raises the voltage of the power, and suppliesthe power to the spark plug 423 to make a spark. The transformer fixingpart 465 may be provided to fix the ignition transformer 48. The blowerpipe 464 may be connected with the blower 44 and may serve as a passagefor forcibly delivering air into the burner space 460. The part of theoutside of the transformer fixing part 465 and the part of the outsideof the blower pipe 464 may be spaced apart upward from the combustionchamber cover 28. This is to reduce the amount of heat transferred tothe flame acquisition device 43, which will be described below, bydecreasing a contact area with the combustion chamber cover 28 heated bya combustion reaction.

Fuel Pump Device 45

FIG. 12 is an exploded perspective view of the fuel pump device 45 ofthe oil boiler 1 according to an embodiment of the present disclosure.

The fuel pump device 45 according to an embodiment of the presentdisclosure will be described below with additional reference to FIG. 12.The fuel pump device 45 may be a component for supplying fuel to thefuel nozzle 421. The fuel pump device 45 may include a fuel pump 451 anda fuel pump driving motor 452 and may further include a coupling 453, afuel pump case 455, and a heat dissipation hole 4551.

The fuel pump 451 may be a component including gears for compressing thefuel and delivering the compressed fuel to the fuel nozzle 421.Accordingly, the fuel pump 451 may be a gear pump in which the gears areengaged with each other to compress fluid between the gears and injectthe fluid. The fuel pump 451 may be connected with a fuel pipe 4561,through which the fuel flowing from a fuel storage device (notillustrated) passes, to receive the fuel and may be connected with arecovery pipe 4562 to return the remaining fuel left after injection tothe fuel storage device.

The fuel pump driving motor 452 may be a component that transmits adriving force to the fuel pump 451 to rotate the gears. The fuel pumpdriving motor 452 may be provided separately from the blower drivingmotor 443. Accordingly, as compared with when the blower 44 and the fuelpump 451 are mounted on the same shaft of the same motor and receive adriving force, the amount of eccentricity may be decreased due to areduction in the length of a member used as a shaft, driving torque maybe reduced, and power consumption may be decreased.

The fuel pump driving motor 452 may be controlled by the processor 152such that the fuel pump 451 compresses and supplies the fuel to the fuelnozzle 421 at a first fuel flow rate or a second fuel flow rate higherthan the first fuel flow rate. Accordingly, the fuel pump 451 may supplythe fuel in at least two stages and may supply the fuel to the fuelnozzle 421 at a different fuel flow rate that is not the same as thefirst fuel flow and the second fuel flow rate, in addition to the firstfuel flow rate and the second fuel flow rate described above.

A shaft member 4511 of the fuel pump 451 that is provided to rotate thegears and a driving shaft 4521 of the fuel pump driving motor 452 thatis provided to transmit the driving force of the fuel pump driving motor452 may be connected by the coupling 453.

The coupling 453 may be an Oldham coupling. Accordingly, the drivingforce of the fuel pump driving motor 452 may be transmitted to the gearsof the fuel pump 451 even in an eccentric state in which the shaftmember 4511 of the fuel pump 451 and the driving shaft 4521 of the fuelpump driving motor 452 are not mounted on the same shaft. Furthermore,the fuel pump 451 can be driven with a small torque even in theeccentric state.

The fuel pump device 45 may have the fuel pump case 455 having aninterior space in which the shaft member 4511 of the fuel pump 451, thecoupling 453, and the driving shaft 4521 of the fuel pump driving motor452 are received. The fuel pump case 455 may have the heat dissipationhole 4551 formed therein. The heat dissipation hole 4551 may be anopening that is formed through the fuel pump case 455 and that connectsthe interior space and the outside of the fuel pump case 455. The heatdissipation hole 4551, which is open, may dissipate heat generatedduring coupling. Furthermore, the heat dissipation hole 4551 may beformed in a size to allow for passage of the coupling 453, and thecoupling 453 may be assembled to the shaft member 4511 of the fuel pump451 and the driving shaft 4521 of the fuel pump driving motor 452through the heat dissipation hole 4551.

The processor 152 may control the fuel pump device 45 to supply the fuelto the fuel nozzle 421 at the first fuel flow rate during ignition of amixture. As the fuel pump device 45 supplies the fuel to the fuel nozzle421 at the first fuel flow rate lower than the second fuel flow rate,ignition noise may be reduced, as compared with when the mixture isignited while the fuel is consistently supplied at the second fuel flowrate.

The oil boiler 1 according to an embodiment of the present disclosuremay further include a temperature acquisition device 214 for obtainingthe temperature of the combustion chamber 22. The temperatureacquisition device 214 may be attached to the outside of a surface ofthe outer container 21 that is adjacent to the combustion chamber 22 andmay indirectly obtain the temperature of the combustion chamber 22. Thetemperature acquisition device 214 may be implemented with athermocouple. However, the type of the temperature acquisition device214 and the position thereof are not limited thereto.

The oil boiler 1 that cannot adjust the fuel flow rate at which the fuelpump device 45 delivers the fuel to the fuel nozzle 421 may beconsidered. In this case, when the combustion chamber 22 is determinedto be overheated, the oil boiler 1 may stop the supply of fuel to stop acombustion reaction such that the combustion chamber 22 is cooled. In acase where the combustion chamber 22 is excessively cooled so thatheating by a combustion reaction is required, the fuel pump device 45may supply the fuel to the fuel nozzle 421 again to ignite the mixtureand generate a flame. As this operation is repeated, ignition noise maybe consistently generated, and a reverse flow of combustion gas or airby explosion during the ignition may occur.

The processor 152 according to an embodiment of the present disclosuremay be electrically connected with the temperature acquisition device214. This is to allow the processor 152 to appropriately control thefuel pump device 45 depending on the temperature of the combustionchamber 22 to solve the aforementioned problem.

Specifically, when the fuel pump device 45 supplies the fuel to the fuelnozzle 421 at the second fuel flow rate, the combustion chamber 22 maybe overheated, and the temperature of the combustion chamber 22 obtainedby the temperature acquisition device 214 may exceed a predeterminedupper limit. In this case, the processor 152 may control the fuel pumpdevice 45 to supply the fuel to the fuel nozzle 421 at the first fuelflow rate. Accordingly, the combustion chamber 22 may be prevented frombeing overheated. In addition, the amount of nitrogen oxide generateddue to the high temperature may be reduced, and the combustion reactionmay not be stopped.

When the fuel pump device 45 supplies the fuel to the fuel nozzle 421 atthe first fuel flow rate, the combustion chamber 22 may be cooled, andthe temperature of the combustion chamber 22 obtained by the temperatureacquisition device 214 may not reach a predetermined lower limit. Inthis case, the processor 152 may control the fuel pump device 45 tosupply the fuel to the fuel nozzle 421 at the second fuel flow rate.Accordingly, a situation in which the combustion chamber 22 is cooledand therefore heating water is not effectively heated may be prevented,and ignition noise and reverse flow that occur in the situation in whichthe combustion reaction is re-initiated may be prevented.

Air Supply Pipe Part

The air supply pipe part may include the air supply pipe 51 and acorrugated pipe 52. An inlet of the corrugated pipe 52 may be connectedto an air supply adaptor 3333 of the flue connecting adaptor 333, andair introduced into the flue connecting adaptor 333 from the flue 53 issupplied to the corrugated pipe 52. An outlet of the corrugated pipe 52may be connected to an inlet 5110 of the air supply pipe 51 to supplythe air to the air supply pipe 51. An inlet part 511 of the air supplypipe 51 that forms the inlet 5110 of the air supply pipe 51 may beinserted into the outlet of the corrugated pipe 52, and therefore thecorrugated pipe 52 and the air supply pipe 51 may be coupled together.The outlet 5120 of the air supply pipe 51 may be connected to theopening of the impeller case 442 to supply the air to the blower 44.

That is, the air supply pipe part may include the air supply pipe 51 andthe corrugated pipe 52 that are continuous with each other, and an inletand an outlet of the air supply pipe part may correspond to the inlet ofthe corrugated pipe 52 and the outlet 5120 of the air supply pipe 51,respectively. The air supply pipe part having the above-describedstructure may guide external air to the blower 44 to guide the air tothe air nozzle 422.

The corrugated pipe 52 may be a tube having a corrugated outer surfacein an accordion form and may be variable in overall shape and length.Accordingly, the positions of the inlet and the outlet of the corrugatedpipe 52 may be freely determined, and the corrugated pipe 52 may beeasily deformed. Even though the position of the air supply pipe 51 orthe position of the air supply adaptor 3333 of the flue connectingadaptor 333 is changed, the corrugated pipe 52 may easily connect theflue connecting adaptor 333 and the air supply pipe 51. A flexiblematerial may be selected to be the material of the corrugated pipe 52.

The total length of the air supply pipe 51 may be greater than thelength of a straight line that connects the inlet 5110 of the air supplypipe 51 and the outlet 5120 of the air supply pipe 51. That is, the airsupply pipe 51 may have bent or curved portions without being formed ina cylindrical pipe shape in which an inlet and an outlet are connectedstraight.

During ignition of a mixture, the pressure of combustion gas and airthat flow back to the blower 44 from the interior space 220 of thecombustion chamber 22 by explosion of the mixture may be generated andapplied. However, the pressure of air that acts from the blower 44 tothe interior space 220 by the blower 44 may also be present. At leastone of the total length of the air supply pipe 51 and the inner diameterof the air supply pipe 51 may be determined based on the differencebetween the two pressures.

Specifically, based on the magnitudes of the two pressures describedabove, the total length of the air supply pipe 51 may be formed suchthat the combustion gas or the air that flows backward does not passthrough the air supply pipe 51. As the length of the air supply pipe 51is increased, the magnitude of resistance against the fluid flowingbackward may be increased.

Furthermore, based on the magnitudes of the two pressures describedabove, the inner diameter of the air supply pipe 51 may be formed suchthat the combustion gas or the air that flows backward does not passthrough the air supply pipe 51. As the inner diameter of the air supplypipe 51 is decreased, the magnitude of resistance against the fluidflowing backward may be increased.

For example, the pressure generated in the interior space 220 duringignition may be about 150 mmH₂O. The wind pressure of the blower 44during the ignition may be about 100 mmH₂O. Accordingly, the innerdiameter and the total length of the air supply pipe 51 may be formedsuch that the air supply pipe 51 has resistance by which an air flowdoes not occur even when the difference in pressure between the inlet5110 and the outlet 5120 of the air supply pipe 51 is equal to 50 mmH₂Othat corresponds to the difference between the two pressures.

The air supply pipe 51 may include a plurality of linear portions 514and a plurality of connecting portions 513 so as to have bent or curvedportions. The plurality of linear portions 514 may extend straight, andeach of the connecting portions 513 may connect two linear portions 514adjacent to each other such that the two linear portions 514 areperpendicular to each other. As the air supply pipe 51 has at least oneconnecting portion 513, the air supply pipe 51 may have a bent shape asillustrated. Furthermore, in the limited interior space 220 of the case10, the air supply pipe 51 may have a long length and may occupy aminimum space. The linear portions 514 and the connecting portions 513may form the above-described pipe part.

FIG. 13 is a sectional view of the air supply pipe 51 of the oil boiler1 according to an embodiment of the present disclosure. An internalstructure of the air supply pipe 51 and control of the blower 44 usingthe same will be described below with additional reference to FIG. 13.Differential pressure measuring instruments 5161 and 5162 may bedisposed at two points of the air supply pipe 51. The differentialpressure measuring instrument located at an upstream side along the flowdirection of air when the blower 44 operates may be the firstdifferential pressure measuring instrument 5161, and the differentialpressure measuring instrument located at a downstream side may be thesecond differential pressure measuring instrument 5162. The differentialpressure acquisition device 47 may be connected to the two differentialpressure measuring instruments 5161 and 5162 to obtain a differentialpressure between the two differential pressure measuring instruments5161 and 5162. The differential pressure acquisition device 47 may be adevice for obtaining a differential pressure between the two pointsusing a diaphragm. However, the method is not limited thereto.

An orifice plate 157 may be disposed between the two points. The orificeplate 517 may be a structure that causes a pressure drop of an air flowand generates a differential pressure between the two points, in whichthe pressure measured by the second differential pressure measuringinstrument 5162 is lower than the pressure measured by the firstdifferential pressure measuring instrument 5161. Specifically, theorifice plate 517 may be implemented with a plate having, in the centerthereof, a hole having a gradually decreasing cross-section along an airflow direction and may cause a pressure drop when air flows.

An adaptor 515 may be disposed upstream of the orifice plate 517 withrespect to the flow direction of air. The adaptor 515 may include theinlet 5110 of the air supply pipe 51 and may have, in a positionadjacent to the orifice plate 517, an inner diameter larger than theinner diameter of a pipe disposed downstream of the orifice plate 517.However, in the other positions, the adaptor 515 may have an innerdiameter smaller or larger than the above-described inner diameterdepending on the capacity of the oil boiler 1. The adaptor 515 may beremovably coupled with the pipe located downstream of the orifice plate517 with respect to the orifice plate 517.

The differential pressure acquisition device 47 may be electricallyconnected with the processor 152 and may transfer an obtaineddifferential pressure to the processor 152. The processor 152 maycontrol the blower 44, based on the obtained differential pressure. Theimpeller 441 of the blower 44 may rotate at one of a plurality ofdifferent speeds.

At a reference differential pressure that is a predetermined appropriatedifferential pressure, air may be smoothly supplied to the burner 42 tocause a combustion reaction in a state in which the oil boiler 1normally operates. However, when condensate is not smoothly drained orresistance to the flow of combustion gas is generated by sootaccumulated in a passage of the combustion gas, even though the blower44 identically operates, the flow rate of air supplied to the burner 42may be decreased, and the pressure of the second differential pressuremeasuring instrument 5162 may be increased. In this case, the pressuremeasured by the first differential pressure measuring instrument 5161may be the same, and therefore the differential pressure may be lowerthan the reference differential pressure.

The oil boiler 1 in which the blower 44 rotates at the same speed may beconsidered. In the oil boiler 1, the blower 44 may not be controlleddepending on a change in differential pressure, and therefore nocountermeasure may be present even when an impediment to the flow ofcombustion gas occurs. Accordingly, the flow rate of air supplied to theburner 42 may be gradually decreased, and a flame may be finallyextinguished so that the boiler may stop operating.

However, the processor 152 of the oil boiler 1 according to anembodiment of the present disclosure may control the blower 44 tomaintain the reference differential pressure. When an obtaineddifferential pressure is lower than the reference differential pressure,the processor 152 may control the blower 44 to increase the rotatingspeed of the impeller 441. Accordingly, the decreasing differentialpressure may reach the reference differential pressure again, and thedecreasing air flow rate may be increased again so that a state in whicha uniform and smooth combustion reaction occurs in the burner 42 may bemaintained.

Even though resistance in the path along which combustion gas flowsdisappears for some reason and the impeller 441 of the blower 44 rotatesat the same speed, an air flow rate may be increased, and an obtaineddifferential pressure may exceed the reference differential pressure. Inthis case, the processor 152 may control the blower 44 to reduce therotating speed of the impeller 441. Accordingly, the increasingdifferential pressure may reach the reference differential pressureagain, and the increasing air flow rate may be decreased again so that astate in which a uniform and smooth combustion reaction occurs in theburner 42 may be maintained.

Trap Device 32

FIG. 14 is a sectional view of the trap device 32 of the oil boiler 1according to an embodiment of the present disclosure. The trap device 32of the oil boiler 1 according to an embodiment of the present disclosurewill be described below with reference to FIG. 14.

The trap device 32 may be a component through which condensate drainedthrough the condensate pipe 341, which is connected to the separator 312included in the condensate receiver 31, passes. The condensate may bedrained to the outside through the trap device 32. However, combustiongas cannot be released like the condensate and may be released throughonly the duct 33 and the flue 53.

The trap device 32 may include a buoyant body trap 321 and a U-shapedtrap 322. The buoyant body trap 321 may include a storage tank 3212having a space in which water is stored and a buoyant body 3211 disposedin the storage tank 3212. A condensate inflow part 320 connected withthe condensate pipe 341 may be connected to the top of the storage tank3212 to deliver the condensate to the storage tank 3212.

The buoyant body 3211 may be floated or sunk by water stored in thebuoyant body trap 321. Here, the stored water may be condensate orseparate water stored for initial boiler operation. An intermediatedrain hole 3213 may be formed through the bottom of the storage tank3212, and a seating part 3214 may be formed along the periphery of theintermediate drain hole 3213. The buoyant body 3211 may be seated on theseating part 3214 or may be separated from the seating part 3214. Whenthe buoyant body 3211 is floated by the stored water, the buoyant body3211 may be separated from the seating part 3214 to open theintermediate drain hole 3213, and the stored water may be drained. Whenthe stored water is drained so that the buoyant body 3211 is sunk, thebuoyant body 3211 may be seated on the seating part 3214 to close theintermediate drain hole 3213. The condensate may be drained through theintermediate drain hole 3213 in this way. However, the buoyant body trap321 may operate so as not to release combustion gas.

The U-shaped trap 322 may be a trap including a first outflow space 3221and a second outflow space 3222. The U-shaped trap 322 may have astructure that acts as a trap in which the water drained from thebuoyant body trap 321 is stored to prevent combustion gas from escaping.The first outflow space 3221 may be a space disposed below theintermediate drain hole 3213 of the buoyant body trap 321 to store thewater drained downward D from the buoyant body trap 321. The secondoutflow space 3222 may be a space extending upward from the firstoutflow space 3221. When the volume of the water stored in the firstoutflow space 3221 is greater than the volume of the first outflow space3221, the water may start to fill the second outflow space 3222. Thesecond outflow space 3222 may extend upward from the first outflow space3221 and may be formed to surround the storage tank 3212. The secondoutflow space 3222 may form a U-shaped trap together with the firstoutflow space 3221.

Part of a trap inner wall 3231 that defines the second outflow space3222 may have a smaller height than the other parts and may have acondensate passage 3223 like an opening. When the water level reachesthe height of the condensate passage 3323 while the water fills thesecond outflow space 3222, the water may be drained to an outflowcontainer 323 through the condensate passage 3223.

The outflow container 323 may be a container in which the water drainedfrom the second outflow space 3222 is stored and from which the water isdrained. An external drain hole 3232 connected with a final drain pipe340 may be formed in the outflow container 323 to drain the stored waterto the outside of the oil boiler 1 through the final drain pipe 340extending to the outside of the case 10. That is, the condensatesupplied from the condensate receiver 31 may be delivered to the outflowcontainer 323 through each trap and may be drained to the outsidethrough the external drain hole 3232 and the final drain pipe 340. Amaterial for performing appropriate treatment on the acidic condensatemay be disposed in a drain space 3230 that is an interior space definedby the outflow space 323.

The outflow container 323 may have a drain opening 3233 and a safetyopening 3234 formed therein. A drain valve 343 and a safety valve 342may be connected to the drain opening 3233 and the safety opening 3234through a drain line 3431 (refer to FIG. 3) and a safety line 3421(refer to FIG. 3), respectively. The drain valve 343 may be connected toa lower side of the empty space 210 and may be formed to be opened orclosed to drain heating water received in the empty space 210 to move,repair, or clean the oil boiler 1. The safety valve 342 may be a valvefor lessening excessively high pressure of the heating water received inthe empty space 210. The safety valve 342 may be formed to be opened orclosed. The safety valve 342 may drain the heating water to decrease thepressure in the empty space 210. The safety valve 342 may remain closedand may be automatically opened when the pressure of the heating waterin the empty space 210 reaches a predetermined pressure.

The drain valve 343 and the safety valve 342 may remain closed such thatthe heating water received in the empty space 210 is not drained fromthe empty space 210, and may be automatically opened to drain theheating water to the outside of the oil boiler 1 when a user opens thevalves or a predetermined condition is satisfied. As the drain valve 343and the safety valve 342 are connected to the outflow container 323 ofthe condensate trap in an embodiment of the present disclosure, theheating water may be delivered to the outflow container 323 withoutbeing directly drained from the valves to the outside. According to anembodiment of the present disclosure, as only one final drain pipe 340for draining water to the outside of the case 10 is present, heatinsulation and wall-perforating work that have to be performed for eachpipe may be reduced, and thus the oil boiler 1 may be easily installed,as compared with when each valve and each trap have a pipe extending tothe outside of the case 10 to drain water to the outside.

Connection Form of Flue 53

FIG. 15 is a sectional view illustrating a coupling structure of theflue connecting adaptor 333 and the flue 53 of the oil boiler 1according to an embodiment of the present disclosure.

The coupling structure of the flue connecting adaptor 333 and the flue53 will be described below with additional reference to FIG. 15. Theflue 53 may be a structure for finally guiding combustion gas to theoutside of the case 10 of the oil boiler 1. Accordingly, the flue 53 maybe installed to pass through the case 10. The flue 53 may be connectedto the flue connecting adaptor 333 of the duct 33.

The flue 53 coupled to the oil boiler 1 of the present disclosure mayhave a double pipe structure having inner pipes 5311 and 5321 and outerpipes 5312 and 5322 surrounding the inner pipes 5311 and 5321. That is,the diameters of the outer pipes 5312 and 5322 may be greater than thediameters of the inner pipes 5311 and 5321, and the inner pipes 5311 and5321 and the outer pipes 5312 and 5322 may form concentric circles on ahorizontal plane. Accordingly, a first intervening space may be formedbetween the outer pipes 5312 and 5322 and the inner pipes 5311 and 5321.Air may be guided through the first intervening space.

Furthermore, the flue 53 may include a straight pipe 532 extendingstraight and may further include an elbow 531 having an inlet and anoutlet, the directions of which are perpendicular to each other. Thestraight pipe 532 and the elbow 531 may constitute the flue 53 and mayhave a double pipe structure as described above. That is, the inner pipe5321 and the outer pipe 5322 of the straight pipe 532 may be disposed,and the inner pipe 5311 and the outer pipe 5312 of the elbow 531 thatare connected to the inner pipe 5321 and the outer pipe 5322 of thestraight pipe 532 may be disposed.

The flue connecting adaptor 333 may have a double pipe structureincluding an inner adaptor 3331 and an outer adaptor 3332 so as to beconnected with the flue 53 having a double pipe structure. The inneradaptor 3331 may be connected with the inner pipes 5311 and 5321, andthe outer adaptor 3332 may be connected with the outer pipes 5312 and5322. The diameter of the outer adaptor 3332 may be greater than thediameter of the inner adaptor 3331, and the inner adaptor 3331 and theouter adaptor 3332 may form concentric circles on a horizontal plane.The outer adaptor 3332 may surround the inner adaptor 3331. Accordingly,a second intervening space may be formed between the outer adaptor 3332and the inner adaptor 3331.

The tubular inner adaptor 3331 may be formed to supply combustion gas tothe inner pipes 5311 and 5321 through the inner pipes 5311 and 5321 andthe horizontal duct portion 332. In an embodiment of the presentdisclosure, the elbow 531 is expressed as being connected to the flueconnecting adaptor 333. However, the straight pipe 532 may be connectedto the flue connecting adaptor 333.

When the flue 53 is coupled to the flue connecting adaptor 333, thesecond intervening space between an inner surface of the outer adaptor3332 and an outer surface of the inner adaptor 3331 may be connected tothe first intervening space between inner surfaces of the outer pipes5312 and 5322 and outer surfaces of the inner pipes 5311 and 5321.Accordingly, external air delivered from the outside of the case 10 mayreach the second intervening space through the first intervening space.The outer adaptor 3332 may be connected with the air supply adaptor 3333connected with the air supply pipe part and may supply the external airto the air supply pipe part through the air supply adaptor 3333. Due tothis structure, a structure for air supply from the outside needs not tobe provided separately from the flue 53. Furthermore, even though a flueis connected to the flue connecting adaptor 333 in any direction asillustrated in FIGS. 16A to 16D, air supply for the air supply pipe partmay always be possible at a predetermined position in the case 10, andtherefore the flow rate of air supplied may not be affected.

The air supply adaptor 3333 included in the flue connecting adaptor 333may protrude outward from the external adaptor 3332 in the radialdirection. The outer adaptor 3332 and the inner adaptor 3331 may be openupward and may be connected to the elbow 531 of the flue 531 along thevertical direction. The outer adaptor 3332 and the inner adaptor 3331may be open downward and may be connected to the horizontal duct portion332 in the vertical direction. Accordingly, the air supply adaptor 3333may extend in one of the horizontal directions and may be connected tothe corrugated pipe 52 along the extension direction.

The space between the inner surface of the outer adaptor 3332 and theouter surface of the inner adaptor 3331 may be connected to the insideof the air supply adaptor 3333. The corrugated pipe 52 connected to theinlet part 511 of the air supply pipe 51 may be connected to the airsupply adaptor 3333.

The flue 53 may be inserted into and coupled with the flue connectingadaptor 333. The outer diameters of the inner pipes 5311 and 5321 may beequal to or smaller than the inner diameter of the inner adaptor 3331,and therefore the inner pipes 5311 and 5321 may be inserted into theinner adaptor 3331. Likewise, the outer diameters of the outer pipes5312 and 5322 may be equal to or smaller than the inner diameter of theouter adaptor 3332, and therefore the outer pipes 5312 and 5322 may beinserted into the outer adaptor 3332.

The flue connecting adaptor 333 may further include a stopper 3334inside. When the flue 53 is inserted too deep into the flue connectingadaptor 333, the outer pipes 5312 and 5322 may block the inlet of theair supply adaptor 3333 connected to the outer adaptor 3332. The stopper3334 may protrude inward from an inner surface of the inner adaptor 3331in the radial direction. The inner pipes 5311 and 5321 may be stopped bythe stopper 3334 while being inserted downward D, and therefore the flue53 may no longer be inserted downward D. That is, when the flue 53 isinserted into and coupled to the flue connecting adaptor 333, thestopper 3334 may suppress a movement of the inner pipes 5311 and 5321 toa lower position than a predetermined point to prevent the outer pipes5312 and 5322 from blocking the opening formed in the outer adaptor3332.

The height of the stopper 3334 may be a height by which when the innerpipes 5311 and 5321 make contact with the stopper 3334, the outer pipes5312 and 5322 are located in a higher position than the inlet of the airsupply adaptor 3333 so as not to block the air supply adaptor 3333. Aplurality of stoppers 3334 may be disposed to be spaced apart from eachother along the inner surface of the inner adaptor 3331. On a horizontalplane, the outer diameters of the inner pipes 5311 and 5321 may besmaller than the inner diameters of the inner adaptor 3331, but may begreater than the distance from the center of the inner adaptor 3331 tothe stopper 3334.

FIGS. 16A to 16D are perspective views illustrating various forms inwhich the flue 53 is connected to the oil boiler 1 according to anembodiment of the present disclosure.

The outlet of the duct 33 may be disposed in a position spaced apartfrom the upper wall 11 of the case 10 at more than a safety intervalthat is a predetermined interval. The safety interval may be apredetermined interval greater than the outer diameter of the pipe thatconstitutes the straight pipe 532 and the elbow 531 of the flue 53.Accordingly, the straight pipe 532 or the elbow 531 may be disposedbetween the duct 33 and the upper wall 11 of the case 10.

Flue insertion holes 111, 1211, 1231, and 1241 may be formed in theupper wall 11 and the sidewalls 12 that constitute the case 10. The flueinsertion holes 111, 1211, 1231, and 1241 may be openings through whichthe flue 53 passes. When the case 10 has the four sidewalls 12, the flueinsertion holes 111, 1211, 1231, and 1241 may be formed in the upperwall 11 and at least two of the four sidewalls 12. In an embodiment ofthe present disclosure, the flue insertion holes 111, 1211, 1231, and1241 are expressed as being formed in the upper wall 11, the firstsidewall 121, the third sidewall 123, and the fourth sidewall 124,respectively. However, the positions in which the flue insertion holes111, 1211, 1231, and 1241 are formed are not limited thereto.

When the flue 53 is inserted into the flue insertion hole 1121, 1231, or1241 formed in the sidewall 121, 123, or 124, the flue 53 may includethe elbow 531 coupled with the flue connecting adaptor 333 and thestraight pipe 532 facing toward the flue insertion hole 1121, 1231, or1241 of the corresponding sidewall 121, 123, or 124 from the elbow 531along a horizontal direction. When the flue 53 is inserted into the flueinsertion hole 111 formed in the upper wall 11, the flue 53 may includethe straight pipe 532, and the straight pipe 532 may be directly coupledwith the flue connecting adaptor 333.

FIG. 16A illustrates a situation in which a flue 53 a including astraight pipe 532 a and an elbow 531 a is inserted into the flueinsertion hole 1231 formed in the third sidewall 123, FIG. 16Billustrates a situation in which a flue 53 b including a straight pipe532 b and an elbow 531 b is inserted into the flue insertion hole 1211formed in the first sidewall 121, FIG. 16C illustrates a situation inwhich a flue 53 c including a straight pipe 532 c and an elbow 531 c isinserted into the flue insertion hole 1241 formed in the fourth sidewall124, and FIG. 16D illustrates a situation in which a flue 53 including astraight pipe 532 d is inserted into the flue insertion hole 111 formedin the upper wall 11. In the drawings, the remaining walls other thanthe second sidewall 122 constituting the case 10 are shown by dottedlines such that the connecting state of the flue 53 and the flueconnecting adaptor 333 is more easily recognized.

The elbow 531 connected to the flue connecting adaptor 333 may beconnected, through the straight pipe 532, with one of the plurality offlue insertion holes 1211, 1231, and 1241 formed in the sidewalls 12. Inthis state, the elbow 531 may be connected with another one of the flueinsertion holes 1211, 1231, and 1241 through the straight pipe 532 byrotating while maintaining the coupling with the flue connecting adaptor333.

For example, as illustrated in FIG. 16A, the elbow 531 a may be disposedto face the third sidewall 123 in the state of being connected to theflue connecting adaptor 333. In this state, the elbow 531 a may beconnected to the flue insertion hole 1231, which is formed in the thirdsidewall 123, through the straight pipe 532 a.

In this state, as illustrated in FIG. 16B, the elbow 531 b may bedisposed to face the first sidewall 121 by rotating the elbow 531 awhile the coupling with the flue connecting adaptor 333 is maintained.In the state of FIG. 16B, the elbow 531 b may be connected to the flueinsertion hole 1211, which is formed in the first sidewall 121, throughthe straight pipe 532 b.

As described above, when the flue connecting adaptor 333 according to anembodiment of the present disclosure is used, the flue 53 may beinserted into the flue insertion hole 1211, 1231, or 1241 formed in eachof the sidewalls 12 by rotating the flue 53 about the axis facing thevertical direction while the connection of the flue connecting adaptor333 and the flue 53 is maintained. Accordingly, even when there is alimitation in the direction in which the flue 53 is provided in a spacein which the oil boiler 1 is installed, the flue 53 may be provided andconnected to the oil boiler 1 in a possible direction.

As the flue connecting adaptor 333 does not move or rotate in theprocess of changing the connection position of the flue 53, the positionof the air supply adaptor 3333 where the corrugated pipe 52 of the airsupply pipe part is connected with the duct 33 is not changed.Accordingly, deformation of the air supply pipe part may be prevented,and thus air may be stably supplied to the air supply pipe part.

Flame Acquisition Device 43

The oil boiler 1 according to an embodiment of the present disclosuremay further include the flame acquisition device 43. FIG. 17 is aperspective view of the burner housing 46 of the oil boiler 1 accordingto an embodiment of the present disclosure. Referring to FIGS. 8, 9, and17, the burner housing 46 may include a sensor hole forming part 463. Asensor hole 4630 may be defined, and the flame acquisition device 43 maybe inserted into the sensor hole 4630.

The flame acquisition device 43 may be a component that obtains featuressuch as temperature from a flame. The flame acquisition device 43 may bea UV sensor that receives ultraviolet light generated from a flamelocated in the combustion chamber 22 and generates a measurement signal.The flame acquisition device 43 may be electrically connected with theprocessor 152 and may transfer the generated measurement signal to theprocessor 152 such that the processor 152 uses the measurement signalfor computation. A presence or absence of a flame in the interior space220 may be determined by the flame acquisition device 43, and thereforewhether a combustion reaction occurs may be determined.

The flame acquisition device 43 may be sensitive to temperature.Accordingly, when high-temperature heat generated in the combustionchamber 22 is easily transferred to the flame acquisition device 43, theflame acquisition device 43 may fail to perform a function thereof.

The flame acquisition device 43 has to be able to identify a flamegenerated in the interior space 220 of the combustion chamber 22.Accordingly, the flame acquisition device 43 may be disposed in aposition where the interior space 220 of the combustion chamber 22 isvisible through a flame monitoring hole 4241 that is an opening formedin the burner fixing plate 424. In an embodiment of the presentdisclosure, the flame monitoring hole 4241 may be formed to be open inthe vertical direction, and the flame acquisition device 43 may beinserted into the sensor hole 4630 formed in the vertical direction.Accordingly, the sensor hole 4630 may be connected to the interior space220 through the flame monitoring hole 4241, and a flame directeddownward D may be identified through the flame monitoring hole 4241.

Specifically, the fixing plate portion 4243 of the burner fixing plate424 may include a first surface exposed to the interior space 220 and asecond surface opposite to the first surface. The flame monitoring hole4241 may be formed through the fixing plate portion 4241 from the firstsurface to the second surface. The flame acquisition device 43 may beinstalled to be spaced apart upward from the second surface.

The sensor hole 4630 may be defined by being surrounded by the sensorhole forming part 463 that is part of the burner housing 46. The sensorhole 4630 may be connected to the outside such that the flameacquisition device 43 is inserted into the sensor hole 4630 from theoutside. Specifically, to form the burner space 460 between the burnerhousing 460 and the burner fixing plate 424, the burner housing 46 mayhave a housing upper wall 466 spaced apart upward from the burner fixingplate 424. The sensor hole forming part 463 may have a tubular shapeextending downward from the housing upper wall 466. The sensor hole 4630may be defined in an empty space of the sensor hole forming part 463.

The sensor hole forming part 463 may include a cooling hole 4631 that ispartly open to connect the sensor hole 4630 and the burner space 460.The cooling hole 4631 may allow for introduction of air to perform aircooling on the sensor hole forming part 463 and the flame acquisitiondevice 43. The cooling hole 4631 may be open toward the fuel nozzle 421.

The sensor hole 4630 may be disposed on the opposite side to the blower44 with respect to the fuel nozzle 421 to minimize an influence on theburner space 460 and the blower 44 by combustion gas or air in thecombustion chamber 22 that flows backward through the sensor hole 4630.Specifically, the blower 44 and the burner housing 46 may be connectedwith each other, and air may be introduced from the blower 44 into theburner space 460 through an air inlet 4640. The cooling hole 4631 may belocated on the opposite side to the air inlet 4640 with respect to thefuel nozzle 421. A lower end of the flame acquisition device 43 insertedinto the sensor hole 4630 may be spaced apart upward from an upper endof the cooling hole 4631, and the flame acquisition device 43 may belocated above the cooling hole 4631.

To minimize the amount of fluid introduced into the sensor hole 4630through the flame monitoring hole 4241, the diameter of the flamemonitoring hole 4241 may be smaller than the inner diameter of a flamemonitoring pipe 4242 that has a tubular shape and that is disposed abovethe flame monitoring hole 4241. To reduce the amount of air introducedinto the flame monitoring hole 4241 through the cooling hole 4631, theflame monitoring pipe 4242 may surround the flame monitoring hole 4241and may protrude upward from the burner fixing plate 424. That is, theflame monitoring pipe 4242 may surround the flame monitoring hole 4241and may protrude toward the sensor hole 4630 from the second surface. Asthe flame monitoring pipe 4242 is disposed, less nitrogen oxide may begenerated, as compared with when the flame monitoring pipe 4242 is notdisposed.

The cross-section of the flame monitoring hole 4241 on a horizontalplane may be 14% to 22% of the cross-section of a hole defined insidethe flame monitoring pipe 4242 by the flame monitoring pipe 4242. Whenthe cross-section of the flame monitoring hole 4241 exceeds the upperlimit, an excessive amount of air may flow through the flame monitoringhole 4241. Accordingly, recirculation of combustion gas may bedisadvantageous, and nitrogen oxide may be increased. When thecross-section of the flame monitoring hole 4241 is smaller than thelower limit, it may be impossible to observe a flame of the flameacquisition device 43 through the flame monitoring hole 4241.

Upper part of the flame monitoring pipe 4242 may be inserted into thesensor hole 4630, and the length by which the flame monitoring pipe 4242overlaps the sensor hole forming part 463 in the vertical direction maybe smaller than 50% of the length of the flame monitoring pipe 4242 inthe vertical direction. This is to reduce the degree to which heattransferred upward from the combustion chamber 22 through the flamemonitoring pipe 4242 is transferred to the flame acquisition device 43through the sensor hole forming part 463.

An upper end of the flame monitoring pipe 4242 may be located at thesame height as the sensor hole forming part 463 in the verticaldirection. The upper end of the flame monitoring pipe 4242 may not belocated in a lower position than a lower end of the sensor hole formingpart 463. This is because if the upper end of the flame monitoring pipe4242 and the lower end of the sensor hole forming part 463 do not meetor overlap each other, an excessive amount of air may pass through theflame monitoring hole 4241 so that a recirculation flow rate ofcombustion gas may be reduced and nitrogen oxide may be increased.

Furthermore, the upper part of the flame monitoring pipe 4242, which isinserted into the sensor hole 4630, may be spaced apart inward from aninner surface of the sensor hole forming part 463 so as not to makecontact with the inner surface of the sensor hole forming part 463. Whenboth the inner surface of the sensor hole forming part 463 and the flamemonitoring pipe 4242 are formed in a cylindrical shape, the innerdiameter of the sensor hole forming part 463 may be greater than theouter diameter of the flame monitoring pipe 4242.

Due to the shapes of the above-described components, the amount of heattransferred to the flame acquisition device 43 may be reduced, and thusthe flame acquisition device 43 may smoothly operate.

As described above, the oil boiler 1 may include the outer container 21,the combustion chamber 22, the lower cover 29, and the flue tubes 23,the burner 42, and the flame tube part 41 including the recirculationholes 413. Accordingly, the oil boiler 1 may generate a blue flame fromfuel of an oil type and may reduce nitrogen oxide.

Further, as described above, the oil boiler 1 may include the combustionchamber 22, the burner 42, the blower 44, the air supply pipe 51 havinga total length greater than the length of a straight line connecting theinlet and the outlet straight, and the heat exchanger. Accordingly, theoverall height of the oil boiler 1 may be reduced, and the oil boiler 1may be located within a limited space.

Furthermore, as described above, the oil boiler 1 may include thecombustion chamber 22, the burner 42, the blower 44, the air supply pipe51, the duct 33 including the flue connecting adaptor 333 to which thecorrugated pipe 52 and the flue 53 are connected, the heat exchanger,and the case 10. Accordingly, the flue 53 may be installed in variousdirections. Also, the position where the air supply pipe 51 receives airthrough the corrugated pipe 52 may be fixed irrespective of thedirection in which the flue 53 is installed, and thus the flow rate ofair supplied may be stably maintained.

Moreover, as described above, the flame tube part 41 may include theupper flame tube 412 having an upper coupling part and the lower flametube 411 having a lower coupling part coupled to the upper couplingpart. Accordingly, the flame tube part 41 may be assembled in an easyand simple manner and may not be corroded or damaged when heated. Also,heat transfer to the combustion chamber cover 28 by the flame tube part41 may be reduced.

In addition, as described above, the oil boiler 1 may include thecombustion chamber 22, the flame acquisition device 43 installed in thesensor hole 4630, the burner 42 having, in a position space apart fromthe flame acquisition device 43, the flame monitoring hole 4241connecting the interior space 220 and the sensor hole 4630, and the heatexchanger. Accordingly, the amount of heat transferred to the flameacquisition device 43 may be reduced, and the flame acquisition device43 may smoothly operate to enable the state of a flame to be identified.

However, the components of the oil boiler 1 described above may becombined differently from the exemplary combination as needed.

According to the embodiments of the present disclosure, the oil boilermay generate a blue flame while using fuel of an oil type, therebyreducing the amount of nitrogen oxide generated when the oil boileroperates.

Furthermore, the flue may be installed in various directions. Inaddition, the position where the air supply pipe receives air may befixed irrespective of the direction in which the flue is installed, andthus the flow rate of air supplied may be stably maintained.

Hereinabove, even though all of the components are coupled into one bodyor operate in a combined state in the description of the above-mentionedembodiments of the present disclosure, the present disclosure is notlimited to these embodiments. That is, all of the components may operatein one or more selective combination within the range of the purpose ofthe present disclosure. It should be also understood that the terms of“include”, “comprise” or “have” in the specification are “open type”expressions just to say that the corresponding components exist and,unless specifically described to the contrary, do not exclude but mayinclude additional components. Unless otherwise defined, all terms usedherein, including technical and scientific terms, have the same meaningas those generally understood by those skilled in the art to which thepresent disclosure pertains. Such terms as those defined in a generallyused dictionary are to be interpreted as having meanings equal to thecontextual meanings in the relevant field of art, and are not to beinterpreted as having ideal or excessively formal meanings unlessclearly defined as having such in the present application.

Hereinabove, although the present disclosure has been described withreference to exemplary embodiments and the accompanying drawings, thepresent disclosure is not limited thereto, but may be variously modifiedand altered by those skilled in the art to which the present disclosurepertains without departing from the spirit and scope of the presentdisclosure claimed in the following claims. Therefore, the exemplaryembodiments of the present disclosure are provided to explain the spiritand scope of the present disclosure, but not to limit them, so that thespirit and scope of the present disclosure is not limited by theembodiments. The scope of the present disclosure should be construed onthe basis of the accompanying claims, and all the technical ideas withinthe scope equivalent to the claims should be included in the scope ofthe present disclosure.

What is claimed is:
 1. An oil boiler comprising: an outer containerhaving openings at opposite ends thereof and an empty space therein, theempty space being connected to the openings at the opposite ends; acombustion chamber configured to cover an opening at an upper end of theouter container, the combustion chamber being located in the empty spaceof the outer container and having an interior space in which acombustion reaction occurs; a lower cover spaced apart downward from thecombustion chamber and configured to cover an opening at a lower end ofthe outer container; a plurality of flue tubes provided in the emptyspace of the outer container to heat heating water flowing in the emptyspace of the outer container by guiding combustion gas generated by thecombustion reaction from the interior space of the combustion chamber tothe outside of the lower cover; a burner including a fuel nozzleconfigured to spray fuel of an oil type into the interior space of thecombustion chamber, an air nozzle configured to inject air into theinterior space, and a spark plug configured to ignite a mixture of thefuel sprayed and the air injected; and a flame tube part configured todefine a tube space by surrounding, in the interior space, a partialspace in which the mixture of the sprayed fuel and the injected air isignited, the flame tube part including a flame tube having an open lowerend and a recirculation hole formed through the flame tube such that thecombustion gas in the interior space is introduced into the flame tubefrom the outside of the flame tube.
 2. The oil boiler of claim 1,further comprising: a combustion guide configured to change a progressdirection of the combustion gas to an upper direction, the combustionguide including a blocking plate horizontally formed in a plate shapeand disposed in the interior space of the combustion chamber so as to bespaced apart from an inner side surface of the combustion chamber, aguide wall extending upward from the blocking plate, the guide wallbeing formed along a periphery of the blocking plate, and a guide legextending downward from the blocking plate, the guide leg beingconfigured to support the blocking plate above an inner bottom surfaceof the combustion chamber.
 3. The oil boiler of claim 1, wherein the airnozzle is formed to surround the fuel nozzle and injects the air throughan air injection opening formed between an inner side surface of the airnozzle and an outer side surface of the fuel nozzle.
 4. The oil boilerof claim 1, further comprising: a buoyant body trap including a storagetank having a space in which water is stored, a buoyant body disposed inthe storage tank and floated or sunk by the stored water, and a seatingpart formed along a periphery of an intermediate drain hole formedthrough a lower surface of the storage tank, wherein the buoyant body isseated on the seating part to close the intermediate drain hole or isseparated from the seating part to open the intermediate drain hole; aU-shaped trap located under the buoyant body trap, the U-shaped trapincluding a first outflow space in which the water drained downward fromthe buoyant body trap is stored and a second outflow space extendingupward from the first outflow space; and a trap device including anoutflow container in which the water drained from the second outflowspace is stored and from which the water is drained to the outside. 5.The oil boiler of claim 4, further comprising: a drain valve configuredto drain the heating water received in the empty space; and a safetyvalve configured to drain the heating water in the empty space todecrease pressure in the empty space, wherein the drain valve and thesafety valve are connected to the outflow container to deliver, to theoutflow container, the water drained through an open one of the drainvalve and the safety valve.
 6. The oil boiler of claim 1, wherein whenwidths defined in two directions extending to be perpendicular to eachother on a horizontal plane are referred to as a first width and asecond width, the flue tubes are provided in a flat tube type in whichthe second width of an internal flow passage through which thecombustion gas passes is smaller than the first width of the internalflow passage.
 7. The oil boiler of claim 1, further comprising: aturbulator inserted into each of the flue tubes to turn a flow of thecombustion gas passing through the flue tube into a turbulent flow, theturbulator including a plate extending in a vertical direction, aplurality of through-portions formed through the plate, and a pluralityof protrusions protruding from the plate, wherein the turbulator furtherincludes a stopper protruding form an upper end of the plate in ahorizontal direction so as to be stopped by an inner bottom surface ofthe combustion chamber when the turbulator is inserted into the fluetube downward from above the flue tube.
 8. The oil boiler of claim 1,further comprising: a blower; a blower pipe configured to connect theblower and the burner; and a damper including a flap provided in theblower pipe so as to be rotatable between a first position for openingthe blower pipe and a second position for closing the blower pipe,wherein the flap is located at the first position by being pressed by anair flow generated by the blower when the blower operates, and the flapis located at the second position by the weight of the flap when theblower does not operate.
 9. The oil boiler of claim 1, furthercomprising: a blower including an impeller configured to compress theair and deliver the compressed air to the air nozzle and a blowerdriving motor configured to transfer, to the impeller, a driving forcefor rotating the impeller; and a fuel pump device including a fuel pumpincluding gears configured to compress the fuel and deliver thecompressed fuel to the fuel nozzle and a fuel pump driving motorprovided separately from the blower driving motor and configured totransmit, to the gears, a driving force for rotating the gears.
 10. Theoil boiler of claim 9, wherein a shaft member of the fuel pumpconfigured to rotate the gears and a driving shaft of the fuel pumpdriving motor configured to transmit a driving force of the fuel pumpdriving motor are connected by a coupling that is an Oldham coupling.11. The oil boiler of claim 10, wherein the fuel pump device furtherincludes a fuel pump case having an interior space in which the shaftmember of the fuel pump, the coupling, and the driving shaft of the fuelpump driving motor are received, and a heat dissipation hole formedthrough the fuel pump case and connected to the interior space, the heatdissipation hole being formed in a size to allow for passage of thecoupling and configured to dissipate heat generated during coupling. 12.The oil boiler of claim 9, further comprising: a processor electricallyconnected with the fuel pump device, wherein the processor controls thefuel pump to supply the fuel to the fuel nozzle at a first fuel flowrate that is a predetermined flow rate or at a second fuel flow ratehigher than the first fuel flow rate.
 13. The oil boiler of claim 12,further comprising: a temperature acquisition device configured toobtain temperature of the combustion chamber, wherein the processor isadditionally electrically connected with the temperature acquisitiondevice and controls the fuel pump device to supply the fuel to the fuelnozzle at the first fuel flow rate in a case where the temperature ofthe combustion chamber obtained by the temperature acquisition deviceexceeds a predetermined upper limit when the fuel pump device suppliesthe fuel to the fuel nozzle at the second fuel flow rate.
 14. The oilboiler of claim 1, further comprising: a case in which the outercontainer is received, wherein the case includes handles provided on twosidewalls facing each other in a horizontal direction among a pluralityof walls configured to define the case.
 15. The oil boiler of claim 1,wherein the outer container is formed of stainless steel.
 16. The oilboiler of claim 11, further comprising: a flue configured to release thecombustion gas to the outside, wherein the flue is formed of plastic.